Method and apparatus for slicing potatoes

ABSTRACT

A rotary potato cutter has a stationary knife with an undulating cutting edge to obtain a corrugated surface on a potato slice. The outer surface of the knife is grooved along its full length to guide the slice therealong as the cut is made. Rotating crosscut knives adapted to cut the slice transversely into french fry size strips having cutting edges similar to the cutting edge on the stationary knife. Alternate ones of the crosscut knives are offset laterally in opposed directions from the stationary knife such that a ridge on a crosscut knife is 90* out of phase with a ridge on the stationary knife, adjacent crosscut knives being 180* out of phase with each other. Mounting the crosscut knives in this manner results in the surfaces of a potato strip cut by such knives having ridges and valleys therein in opposed relationship, whereby the finally cut potato strip appears to have ridges and valleys therein running substantially continuously therearound.

United States Patent Haubner Feb. 22, 1972 [54] METHOD AND APPARATUS FOR SLICING POTATOES [72] Inventor: John E. Haubner, Portland, Oreg. [73] Assignee: Lamb Weston, Inc., Portland, Oreg. [22] Filed: Aug. 5, 1970 [2l] Appl. No.: 61,189

Primary ExaminerWillie G. Abercrombie Anorney-Buckhorn, Blore, Klarquist and Sparkman [5 7] ABSTRACT A rotary potato cutter has a stationary knife with an undulating cutting edge to obtain a corrugated surface on a potato slice. The outer surface of the knife is grooved along its full length to guide the slice therealong as the cut is made. Rotating crosscut knives adapted to cut the slice transversely into french fry size strips having cutting edges similar to the cutting edge on the stationary knife. Alternate ones of the crosscut knives are offset laterally in opposed directions from the stationary knife such that a ridge on a crosscut knife is 90 out of phase with a ridge on the stationary knife, adjacent crosscut knives being 180 out of phase with each other. Mounting the crosscut knives in this manner results in the surfaces of a potato strip cut by such knives having ridges and valleys therein in opposed relationship, whereby the finally cut potato strip appears to have ridges and valleys therein running substantially continuously therearound.

4 Claims, 7 Drawing Figures PATENTEUFEB22 I972 SHEET 1 BF 2 JOHN E. HAU BNER INVENTOR SPARKMAN NEYS ST &

TTOR

BUCKHORN, BLORE, KLARQUI METHOD AND APPARATUS FOR SLICING POTATOES BACKGROUND OF THE INVENTION This invention relates to a method and apparatus for providing french fry potato strips and, more particularly, to a method and apparatus for providing such strips with serrated or undulating surfaces. Potato strips sliced in this manner are commonly known as crinkle cut.

An apparatus presently-available for cutting french fry size potato strips with serrated sides is manufactured by Urschel Laboratories, Inc., of Valparaiso, Indiana, and is known as the Urschel Model GRL cutter. This machine enables the user to cut french fry size potato strips having serrated or undulating surfaces wherein the amplitude of the undulations is approximately one-sixteenth inch. The aforementioned apparatus, however, will not cut strips with very deep and narrow side serrations, nor is that cutter capable of manufacturing crinkle cut strips wherein opposed surfaces have their ridges and valleys extending in opposed relationship.

Accordingly, it is the primary object of the present invention to provide a method and apparatus for cutting french fry size potato strips having very deep side serrations.

It is a further object of the present invention to provide such a method and apparatus wherein the finally cut strip presents the appearance of having its ridges and valleys running substantially continuously therearound.

It is a further object of the present invention to provide french fry size potato strips having undulating surfaces wherein the amplitude of undulations equals or exceeds oneeighth inch.

SUMMARY OF TI-IE INVENTION The rotary potato cutter of the present invention comprises drum means and impeller means mounted within the drum means and adapted to rotate a potato around the inner peripheral surface thereof. A stationary knife attached to the drum means and adapted to cut a slice from the potato at each revolution of the impeller means has an undulating cutting edge to obtain a corrugated or undulating surface on the potato slice. The outer or slice-supporting surface of the knife is grooved along its full length effectively to guide the slice therealong as the cut is made.

Crosscut knives, mounted for rotation about an axis parallel to the stationary knife, cut the slice transversely thereof into french fry size strips as the slice extends beyond the trailing edge of the stationary knife. Each of the crosscut knives has a cutting edge similar to the cutting edge of the stationary knife. Alternate ones of the crosscut knives are offset laterally in opposed directions from the stationary knife such that a ridge of a crosscut knife is 90 out of phase with a ridge of the stationary knife, adjacent crosscut knives being 180 out of phase with each other.

The surfaces of each of the potato strips cut by the crosscut knives have ridges and valleys therein in opposed relationship, and the finally cut potato strip presents the appearance of having its ridges and valleys running substantially continuously therearound. The apparatus permits the strips to be cut with side serrations deeper and more narrow than was heretofore possible.

The impeller means comprises an impeller plate to push the potatoes circumferentially along the inner peripheral surface of the drum means. The plate has an undulating outer edge which closely fits and meshes with the undulating cutting edge of the stationary knife to assist in pushing all slices cut from the potato through the stationary knife.

The method of the present invention comprises pushing a potato against a stationary knife having an undulating cutting edge to cut a slice from the potato having an undulating surface. The slice is guided along a product supporting surface of the knife adjacent its cutting edge which surface has ridges and valleys therein along its full length complementary with the ridges and valleys of its cutting edge to guide the slice by means of the ridges and valleys therein.

The slice is cut transversely thereof by crosscut knives as it extends beyond the trailing edge of the stationary knife. Alternate ones of such crosscut knives are offset laterally in opposed directions from the stationary knife such that a ridge of a crosscut knife is out of phase with a ridge in the stationary knife.

Since adjacent ones of the crosscut knives are out of phase with each other, the surfaces of each of the potato strips cut by the crosscut knives have ridges and valleys therein in opposed relationship, and the finally out potato strip presents the appearance of having its ridges and valleys running sub stantially continuously therearound.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus suitable for the practice of the present invention.

FIG. 2 is a sectional view through the drum means and crosscut knives of the apparatus of FIG. 1.

FIG. 3 is a view of the potato slice taken on line 3-3 of FIG. 2.

FIG. 4 is a view of the potato strip taken on line 4-4 of FIG. 2.

FIG. 5 is a view taken on line 5-5 of FIG. 2 and developed on a plane to illustrate the relative positions of the edges of the crosscut knives.

' FIG. 6 is a sectional view, to an enlarged scale, of the potato strip taken on line 6-6 of FIG. 4.

FIG. 7 is a side elevational view ofthe strip shown in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and in particular to FIGS. 1 and 2, the cutter 10 therein illustrated is mounted on a support frame 12 and receives potatoes through an inlet chute 14. The potatoes are directed into a slicing shell 16 where a revolving impeller 18 pushes them around the inner peripheral surface 20. A potato 38 is forced through a stationary slicing knife 22 whereupon a slice 36 cut therefrom is itself out by crosscut knives 24 into strips 46 which are discharged through a chute 26. A protective cover 28 encloses the knives 24, and a chute cover 30 diverts the cut strips downwardly as they exit from the machine.

As shown in FIG. 2, a slicing gate 32 bolted to the shell 16 has an adjusting means 34 to control the thickness of each slice 36 cut from the potato 38. A slice guide 40 bolted to the gate 32 retains the slice in position for subsequent transverse cutting.

The crosscut knives 24 are mounted for rotation on a crosscut spindle 42 whose axis 44 is parallel to the plane of the stationary knife 22. The crosscut knives 24 cut the slice 36 into french fry size strips 46 as the slice extends beyond the trailing edge 48 of the knife 22. The size of the second cut is controlled by the number of crosscut knives 24 mounted on the spindle 42 and by the speed of rotation thereof.

A feature of the invention is the stationary slicing knife 22 which makes the initial cut into the potato 38 as the same is rotated inside the slicing shell by the impeller 18. The knife 22 is ground with an undulating cutting edge 50 and is much thicker than those used heretofore. The inner surface 52 is machined flat for attachment to the shell 16 and terminates at its leading edge in an inner cutting surface 54 which is grooved complementarily with the deep undulations in the edge 50 and also curved so that its surface matches the radius of the shell 16. The outer or product supporting surface 56 is similarly grooved along its full length complementarily with the undulations in the edge 50. Such grooving of the surface 56 supports the cutting edge 50 along its full length and effectively guides the potato slice 36 by meshing with the ridges and valleys cut therein. Thus the slice is maintained in a true transverse position as it passes along the surface 56 on its way to the crosscut knives 24.

The trailing edge 48 of the knife 22 is chamfered at its outer edge 58 to permit close clearance between such edge and the cutting edges 60 of the knives 24 since the edge 58 is the point where the slice 36 is supported for transverse cutting. The provision of minimum clearance assures maximum support for each slice prior to its being cut by the knives 24.

The inner peripheral surface 20 of the shell 16 and the adjustable gate 32 are each deeply grooved complementarily with the undulations in the cutting edge 50 of the knife 22. Grooving the shell in this manner enables the potato 38 to be guided with maximum security on its way to the knife 22 to effect a more even cut and to retain the potato in proper orientationas it travels past the slicing knife 22 and back onto the shell 16 for its next revolution. Likewise, grooving the outer or product supporting surface 56 of the knife 22 achieves better control ofthe slice 36 as it travels to the crosscut knives 24.

The crosscut knives 24 are each ground from solid stock and each has an undulating cutting edge 60 which is substantially identical to the undulating cutting edge 50 of the knife 22. The knives 24 are retained in the spindle 42 such that their cutting angle enables them to enter the moving slice 36 and cut down through it with a minimum of interference and tearing action. Each of the knives 24 has a cutting edge 60 that is offset laterally from the knife 22 such that a ridge 62 on a crosscut knife 24 is 90 out of phase with a ridge 64 on the stationary knife 22. Alternate ones of the knives 24 are offset laterally in opposed directions such that the undulations on the cutting edges 60 of adjacent knives 24 are 180 out of phase with each other.

By so positioning the knives 24, the surfaces 66 of each strip 46 cut thereby have ridges and valleys in opposed relationship. (See FIG. 4.) Actually, the remaining surfaces 68 of the strips 46 have ridges and valleys which are in phase with each other (see FIG. 3), but the finally cut strip presents the appearance of having its ridges and valleys running substantially continuously therearound (See FIG. 7.) When a strip is so cut and has an amplitude of undulations equal or exceeding one-eighth inch, it produces a different and much better appearing product than the standard crinkle cut potato. The product is also stronger and less apt to break during handling.

The impeller 18 has curved blades 70 which align and rotate the potato inside the shell 16. A pusher plate 72 bolted to each blade 70 is machined at its outer edge 74 to fit closely and mesh with the ridges and valleys in the undulating cutting edge 50 of the knife 22. The plate 72 thus is enabled to reach into the grooves machined in the shell 16 and gate 32, the undulations on the edge 74 matching the ridges and valleys in the shell 16 and in the curved surface 54 of the knife 22. Alternatively, each of the blades 70 may itself be formed closely to mesh with the grooves in the shell 16, gate 32 and knife 22.

Extending the impeller blades 70 in this manner serves to push all slices cut from the potato 38 through the knife 22. The construction is of particular importance on the last slice taken from each potato. Without it, such last slice would tend to stick or remain in the knife 22 until pushed through by the first slice of the next potato, and this would cause nonuniform cuts.

OPERATION The operation of the apparatus is as follows: A potato 38 is introduced into the slicing shell 16 through the opening in the impeller 18. The blades 70 align and rotate the potato inside the shell, and the centrifugal force caused by such rotation causes the potato to be pressed tightly against the inner peripheral surface 20 with several times its own weight. After the potato travels three-fourths the distance around the shell 16, the first slice 36 is cut therefrom. With each such revolution of the impeller blade 70, an additional slice is cut from the potato, which slice travels past the slice guide 40 and into crosscut knives 24.

The deep ridges and grooves of the undulating cutting edge 50 of the knife 22 form a correspondingly deep undulating surface 68 in the slice 36. The slice is guided along the outer or product supporting surface 56 of the knife 22 by the ridges and valleys which extend along its entire length and which ridges and valleys mesh with the corresponding ridges and valleys in the slice. The transverse position of the slice is thus maintained true as the slice is forced beyond the chamfered trailing edge 48 of the knife 22.

The slice is thereupon cut transversely by the knives 24 to form the strips 46. Since adjacent ones of the knives 24 are l out of phase with each other, the surfaces 66 of each of the strips 46 cut by the knives 24 have ridges and valleys therein out of phase or in opposed relationship with each other. Although the ridges and valleys on the remaining surfaces 68 cut by the stationary knife 22 are in phase, the finally cut potato strip presents the appearance of having its ridges and valleys running substantially continuously therearound.

In summary, the method and apparatus of the invention make it possible to cut french fry size potato strips having very deep side serrations, the ridges and valleys of which present the appearance of running substantially continuously around the strip. This ability to cut potato strips for french frying having very deep and narrow serrations on all sides makes possible the preparation of a distinctly better appearing and better tasting french fry potato product. After frying, the potato has a tender crust on its exterior and a preferred appearance as compared with the normal crinkle cut product. Products made according to the process of the present invention achieve ready consumer acceptance.

Since the crosscut knives 24 are alternately offset out of phase with the undulations in the cutting edge 50 of the stationary knife 22, the deep cut ridges and valleys in the product seem to go completely around the strip, presenting the appearance of an accordion or concertina.

The slicing knife 22 is able to cut ridges and valleys having greater amplitude than has been heretofore possible. The knife 13 has greater cutting edge strength and greater rigidity due to its greater thickness and the fact that it is grooved full length along its outer surface 56. The grooves along the surface 56 serve accurately to guide the product into the crosscut knives. Chamfering the outer trailing edge 48 of the knife 22 achieves closer cutting tolerances and better product support.

The crosscut knives 24 are similarly able to cut ridges and valleys having greater amplitude than was heretofore possible. The knives 24 have greater dimensional accuracy and strength to avoid distortion and to maintain the critical angle of attack.

The deep grooves which are machined into the shell 16 and the gate 32, which grooves match the undulations in the knife 22, serve to guide the potato straight and evenly into the knife 22. Providing the plates 72 to extend the impeller blades 70, which plates 72 closely match the grooves in the shell 16, gate 32 and knife 22, also serves effectively to guide and push each potato slice 36 through the knife 22.

The resulting potato strip is stronger and able to withstand greater mechanical abuse than crinkle cut strips heretofore known. The deeply serrated strip presents an appearance distinctively different from other types of cuts and has a preferred appearance due to color highlights along its high ridges. The finish fried strip has a preferred crispy crunchy exterior due to the deep grooves formed therein, which enable the high ridges to reach higher cooking temperatures in the frying process. The strip is also easier to freeze due to its greater exterior surface per unit weight which provides more contact area with the cold air used for heat removal in the freezing process. The strip also fries quicker in hot oil at a given temperature due to such greater surface area per unit weight.

It is apparent that many modifications and variations may be made in the invention.

I claim:

1, A rotary potato cutter, comprising drum means;

impeller means mounted within said drum means and adapted to rotate a potato around the inner peripheral surface thereof;

101024 our.

a stationary knife attached to said drum means and adapted to cut a slice from said potato at each revolution of said impeller means, said knife having an undulating cutting edge to obtain a corrugated surface on said potato slice,

the outer surface of said knife being grooved along its full length effectively to guide said slice therealong as said cut is made; and a plurality of rotating crosscut knives mounted for rotation about an axis parallel to said stationary knife and adapted to cut said slice transversely thereof into french fry size strips as said slice extends beyond the trailing edge of said stationary knife, each of said crosscut knives having a cutting edge similar to said cutting edge of said stationary knife,

alternate ones of said crosscut knives being offset laterally in opposed directions from said stationary knife such that a ridge of a crosscut knife is 90 out of phase with a ridge of said stationary knife, adjacent crosscut knives being 180 out of phase with each other,

whereby the surfaces of each of said potato strips cut by said crosscut knives have ridges and valleys therein in opposed relationship, the finally cut potato strip presenting the appearance of having its ridges and valleys running substantially continuously therearound.

2. Apparatus as in claim 1 in which said impeller means comprise an impeller plate adapted to push said potato circumferentially along the inner peripheral surface of said drum means, said plate having an undulating outer edge surface closely to fit and mesh with said undulating cutting edge of said stationary knife to push all slices cut from said potato through said stationary knife.

3. Apparatus as in claim 1 in which the bottom of said stationary knife is chamfered at its outer edge thereby to permit close clearance between said outer edge and said cutting edges of said crosscut knives and maximum support for said slice prior to its being cut by each of said crosscut knives.

4. A method of cutting french fry size strips of potato having deeply undulating surfaces and in which at least two of such surfaces have ridges and valleys therein in opposed relationship, comprising pushing a potato against a stationary knife having an undulating cutting edge to cut a slice from said potato having an undulating surface, said stationary knife having a product-supporting surface adjacent said cutting edge, said product-supporting surface having ridges and valleys therein along its full length complementary with the ridges and valleys of said cutting edge;

guiding said slice along said product supporting surface of said stationary knife by means of said ridges and valleys therein; and

cutting said slice transversely thereof as said slice extends beyond the trailing edge of said stationary knife by crosscut knives, alternate ones of which are offset laterally in opposed directions from said stationary knife such that a ridge ofa crosscut knife is out of phase with a ridge of said stationary knife, adjacent ones of said crosscut knives being out of phase with each other, whereby the surfaces of each ofsaid potato strips cut by said crosscut knives have ridges and valleys therein in opposed relationship, the finally cut potato strip presenting the appearance of having its ridges and valleys running substantially continuously therearound. 

1. A rotary potato cutter, comprising drum means; impeller means mounted within said drum means and adapted to rotate a potato around the inner peripheral surface thereof; a stationary knife attached to said drum means and adapted to cut a slice from said potato at each revolution of said impeller means, said knife having an undulating cutting edge to obtain a corrugated surface on said potato slice, the outer surface of said knife being grooved along its full length effectively to guide said slice therealong as said cut is made; and a plurality of rotating crosscut knives mounted for rotation about an axis parallel to said stationary knife and adapted to cut said slice transversely thereof into french fry size strips as said slice extends beyond the trailing edge of said stationary knife, each of said crosscut knives having a cutting edge similar to said cutting edge of said stationary knife, alternate ones of said crosscut knives being offset laterally in opposed directions from said stationary knife such that a ridge of a crosscut knife is 90* out of phase with a ridge of said stationary knife, adjacent crosscut knives being 180* out of phase with each other, whereby the surfaces of each of said potato strips cut by said crosscut knives have ridges and valleys therein in opposed relationship, the finally cut potato strip presenting the appearance of having its ridges and valleys running substantially continuously therearound.
 2. Apparatus as in claim 1 in which said impeller means comprise an impeller plate adapted to push said potato circumferentially along the inner peripheral surface of said drum means, said plate having an undulating outer edge surface closely to fit and mesh with said undulating cutting edge of said stationary knife to push all slices cut from said potato through said stationary knife.
 3. Apparatus as in claim 1 in which the bottom of said stationary knife is chamfered at its outer edge thereby to permit close clearance between said outer edge and said cutting edges of said crosscut knives and maximum support for said slice prior to its being cut by each of said crosscut knives.
 4. A method of cutting french fry size strips of potato having deeply undulating surfaces and in which at least two of such surfaces have ridges and valleys therein in opposed relationship, comprising pushing a potato against a stationary knife having an undulating cutting edge to cut a slicE from said potato having an undulating surface, said stationary knife having a product-supporting surface adjacent said cutting edge, said product-supporting surface having ridges and valleys therein along its full length complementary with the ridges and valleys of said cutting edge; guiding said slice along said product supporting surface of said stationary knife by means of said ridges and valleys therein; and cutting said slice transversely thereof as said slice extends beyond the trailing edge of said stationary knife by crosscut knives, alternate ones of which are offset laterally in opposed directions from said stationary knife such that a ridge of a crosscut knife is 90* out of phase with a ridge of said stationary knife, adjacent ones of said crosscut knives being 180* out of phase with each other, whereby the surfaces of each of said potato strips cut by said crosscut knives have ridges and valleys therein in opposed relationship, the finally cut potato strip presenting the appearance of having its ridges and valleys running substantially continuously therearound. 